QPoint(3qt)

📦 version 3.3.8b, in fedora 43, fedora 44

💖 QPoint 💖

okay bestie, gather round, because today we're talking about QPoint from the Qt 3 docs (yes, qpoint.3qt, the manual page, we love her). QPoint defines a point in the plane. that's it. that's the vibe. a little guy with an x and a y and main character energy. 🎀

✨ SYNOPSIS ✨

#include <qpoint.h>

🫶 Public Members

  • QPoint ()
  • QPoint ( int xpos, int ypos )
  • bool isNull () const
  • int x () const
  • int y () const
  • void setX ( int x )
  • void setY ( int y )
  • int manhattanLength () const
  • QCOORD & rx ()
  • QCOORD & ry ()
  • QPoint & operator+= ( const QPoint & p )
  • QPoint & operator-= ( const QPoint & p )
  • QPoint & operator*= ( int c )
  • QPoint & operator*= ( double c )
  • QPoint & operator/= ( int c )
  • QPoint & operator/= ( double c )
  • bool operator== ( const QPoint & p1, const QPoint & p2 )
  • bool operator!= ( const QPoint & p1, const QPoint & p2 )
  • const QPoint operator+ ( const QPoint & p1, const QPoint & p2 )
  • const QPoint operator- ( const QPoint & p1, const QPoint & p2 )
  • const QPoint operator* ( const QPoint & p, int c )
  • const QPoint operator* ( int c, const QPoint & p )
  • const QPoint operator* ( const QPoint & p, double c )
  • const QPoint operator* ( double c, const QPoint & p )
  • const QPoint operator- ( const QPoint & p )
  • const QPoint operator/ ( const QPoint & p, int c )
  • const QPoint operator/ ( const QPoint & p, double c )
  • QDataStream & operator<< ( QDataStream & s, const QPoint & p )
  • QDataStream & operator>> ( QDataStream & s, QPoint & p )

🌸 DESCRIPTION 🌸

The QPoint class defines a point in the plane. literally. that's her job and she's slaying it. 💅

A point is specified by an x coordinate and a y coordinate. iconic. no notes.

The coordinate type is QCOORD, which is a 32-bit integer. The minimum value of QCOORD is QCOORD_MIN (-2147483648) and the maximum value is QCOORD_MAX (2147483647). yes those are real numbers. yes they're huge. we respect them. 👑

The coordinates are accessed by the functions x() and y(); they can be set by setX() and setY() or by the reference functions rx() and ry().

Given a point p, the following statements are all equivalent — like, same result, different fonts, pick your fave:

p.setX( p.x() + 1 );
p += QPoint( 1, 0 );
p.rx()++;

A QPoint can also be used as a vector. Addition and subtraction of QPoints are defined as for vectors — each component is added separately, no mixing, no drama. You can divide or multiply a QPoint by an int or a double. The function manhattanLength() gives an inexpensive approximation of the length of the QPoint interpreted as a vector.

Example, bestie, watch this:

//QPoint oldPos is defined somewhere else
MyWidget::mouseMoveEvent( QMouseEvent *e )
{
    QPoint vector = e->pos() - oldPos;
    if ( vector.manhattanLength() > 3 )
    ... //mouse has moved more than 3 pixels since oldPos
}

QPoints can be compared for equality or inequality, and they can be written to and read from a QStream. versatile queen. 🦋

See also QPointArray, QSize, QRect, Graphics Classes, and Image Processing Classes.

🎀 MEMBER FUNCTION DOCUMENTATION 🎀

QPoint::QPoint ()

Constructs a point with coordinates (0, 0) (and yeah, isNull() returns TRUE for it). baby's first point. starting from zero, as one does. ✨

QPoint::QPoint ( int xpos, int ypos )

Constructs a point with x value xpos and y value ypos. you give her coordinates, she becomes them. 💖

bool QPoint::isNull () const

Returns TRUE if both the x value and the y value are 0; otherwise returns FALSE. so it's an and situation, not an or situation. both zeros or it's not null. periodt. 💅

int QPoint::manhattanLength () const

Returns the sum of the absolute values of x() and y(), traditionally known as the "Manhattan length" of the vector from the origin to the point. The tradition arises because such distances apply to travelers who can only travel on a rectangular grid, like the streets of Manhattan. 🏙️ you cannot walk diagonally through a building, bestie, that's the whole lore.

This is a useful, and quick to calculate, approximation to the true length: sqrt(pow(x(),2)+pow(y(),2)).

ngl this one's the shortcut queen — fast, cheap, good enough for vibe checks like "did the mouse move more than 3 pixels".

QPoint & QPoint::operator*= ( int c )

Multiplies this point's x and y by c, and returns a reference to this point.

Example:

QPoint p( -1, 4 );
p *= 2;            // p becomes (-2,8)

QPoint & QPoint::operator*= ( double c )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Multiplies this point's x and y by c, and returns a reference to this point.

Example:

QPoint p( -1, 4 );
p *= 2.5;          // p becomes (-3,10)
⚠️ Note that the result is truncated because points are held as integers. so the decimals get left on read. 😭

QPoint & QPoint::operator+= ( const QPoint & p )

Adds point p to this point and returns a reference to this point.

Example:

QPoint p(  3, 7 );
QPoint q( -1, 4 );
p += q;            // p becomes (2,11)

QPoint & QPoint::operator-= ( const QPoint & p )

Subtracts point p from this point and returns a reference to this point.

Example:

QPoint p(  3, 7 );
QPoint q( -1, 4 );
p -= q;            // p becomes (4,3)

QPoint & QPoint::operator/= ( int c )

Divides both x and y by c, and returns a reference to this point.

Example:

QPoint p( -2, 8 );
p /= 2;            // p becomes (-1,4)

QPoint & QPoint::operator/= ( double c )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Divides both x and y by c, and returns a reference to this point.

Example:

QPoint p( -3, 10 );
p /= 2.5;           // p becomes (-1,4)
⚠️ Note that the result is truncated because points are held as integers. again. the ints simply cannot handle the decimals. 🫠

QCOORD & QPoint::rx ()

Returns a reference to the x coordinate of the point.

Using a reference makes it possible to directly manipulate x. living dangerously, love that for you.

Example:

QPoint p( 1, 2 );
p.rx()--;         // p becomes (0, 2)

See also ry().

QCOORD & QPoint::ry ()

Returns a reference to the y coordinate of the point.

Using a reference makes it possible to directly manipulate y. same energy, other axis.

Example:

QPoint p( 1, 2 );
p.ry()++;         // p becomes (1, 3)

See also rx().

void QPoint::setX ( int x )

Sets the x coordinate of the point to x.

See also x() and setY().

Example: t14/cannon.cpp.

void QPoint::setY ( int y )

Sets the y coordinate of the point to y.

See also y() and setX().

Example: t14/cannon.cpp.

int QPoint::x () const

Returns the x coordinate of the point.

See also setX() and y().

Examples:

bestie the original manual just says "Examples:" and then… nothing. no examples. empty. we are simply reporting the facts. 💀

int QPoint::y () const

Returns the y coordinate of the point.

See also setY() and x().

Examples:

same situation. the void. the blank. the "Examples:" with no examples. iconic in a cursed way. 🙈

bool operator!= ( const QPoint & p1, const QPoint & p2 )

Returns TRUE if p1 and p2 are not equal; otherwise returns FALSE. they're giving different vibes.

const QPoint operator* ( const QPoint & p, int c )

Returns the QPoint formed by multiplying both components of p by c.

const QPoint operator* ( int c, const QPoint & p )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Returns the QPoint formed by multiplying both components of p by c.

const QPoint operator* ( const QPoint & p, double c )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Returns the QPoint formed by multiplying both components of p by c.

⚠️ Note that the result is truncated because points are held as integers.

const QPoint operator* ( double c, const QPoint & p )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Returns the QPoint formed by multiplying both components of p by c.

⚠️ Note that the result is truncated because points are held as integers.

const QPoint operator+ ( const QPoint & p1, const QPoint & p2 )

Returns the sum of p1 and p2; each component is added separately. no cross-contamination, we keep it clean. ✨

const QPoint operator- ( const QPoint & p1, const QPoint & p2 )

Returns p2 subtracted from p1; each component is subtracted separately.

const QPoint operator- ( const QPoint & p )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Returns the QPoint formed by changing the sign of both components of p, equivalent to QPoint(0,0) - p. it's giving glow-down, but on purpose. 💅

const QPoint operator/ ( const QPoint & p, int c )

Returns the QPoint formed by dividing both components of p by c.

const QPoint operator/ ( const QPoint & p, double c )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Returns the QPoint formed by dividing both components of p by c.

⚠️ Note that the result is truncated because points are held as integers. yes. again. we know. 🍓

QDataStream & operator<< ( QDataStream & s, const QPoint & p )

Writes point p to the stream s and returns a reference to the stream.

See also Format of the QDataStream operators.

bool operator== ( const QPoint & p1, const QPoint & p2 )

Returns TRUE if p1 and p2 are equal; otherwise returns FALSE. twinning. 👯

QDataStream & operator>> ( QDataStream & s, QPoint & p )

Reads a QPoint from the stream s into point p and returns a reference to the stream.

See also Format of the QDataStream operators.

🔍 SEE ALSO 🔍

Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the license file included in the distribution for a complete license statement.

🧚 AUTHOR 🧚

Generated automatically from the source code. (so if this manual page has a personality, it was grown in a lab. and honestly? slay.)

💀 BUGS 💀

If you find a bug in Qt, please report it as described in http://doc.trolltech.com/bughowto.html. Good bug reports help us to help you. Thank you. 🫶

The definitive Qt documentation is provided in HTML format; it is located at $QTDIR/doc/html and can be read using Qt Assistant or with a web browser. This man page is provided as a convenience for those users who prefer man pages, although this format is not officially supported by Trolltech. (so she's a fan-made remix. we still love her.)

If you find errors in this manual page, please report them to qt-bugs@trolltech.com. Please include the name of the manual page (qpoint.3qt) and the Qt version (3.3.8).

and that's the whole page, bestie!! this little bundle of joy came from Trolltech AS, dated 2 February 2007, and she's from the Qt 3.3.8 era — so she's vintage, she's iconic, and she's still out here defining points in the plane. take care of her. 💖✨🎀🦋

📦 where this page comes from